Nut making machine



Aug. 18, 1936.

D. E. JOHNSON NUT MAKING MACHINE Filed June 5, 1955 Patented Aug. 1.8, 1936 UNH'E'SED STATES PATENT @FFEQE NUT MAKING MACHINE David E. Johnson, Rockford, Ill. Application `lune 3, 1935, Serial No. 24,619 9 Claims. (Cl. 10-75) This invention relates to the formation of nuts of the type which have fine peripheral teeth or serrations extending parallel to the nut axis and adapted to intert with complemental serrations tool by which the nut may be gripped and turned onto a bolt or other threaded member. Y

The general object of the invention is to provide a novel apparatus by which nuts of the above character may be formed with a high degree of accuracy, at low manufacturing cost, and with a minimum amount of equipment and handling. In carrying out this object, the Vinvention contemplates the performance of the serrating and tapplng operations in succession in a single to avoid intermediate handling or positioning of the nut blanks.

A more detailed object is to provide novel apparatus of the above character in which the serrating and tapping operations are performed continuous advance of the a serrating die and a The invention also resides in the novel character of the mechanisms employed and the manner of handling the work blanks. Y

Other objects and advantages of the invention will become apparent from the following detailed description taken in connection with the accompanying drawing, in which Figure 1 is a fragmentary vertical sectional view of a nut making machine embodying the novel features of the present invention.

Fig. 2 is an enlarged section taken along the line2-2 of Fig. l.

YWhile the invention is susceptible of various modifications and alternative constructions, I have shown in the drawing and will herein describe in detail the preferred embodiment, but it is to be understood that I do not thereby intend to limit the invention to the specific form disclosed, but intend to cover all modifications and alternative constructions falling within the spirit and scope of the invention as expressed in the appended claims.

In the drawing, the invention is illustrated in connection with the formation of nuts 3 of the so-called llister type comprising a body 4 having an internally threaded bore 5 and a smooth an- Each blank is then forced axially to cut the ser; 10

serrations l5 in a sleeve I6 surrounding the tapping tool.

is of the so-called continuous tapping type where- 20 machine frame 2| through the medium of a bear- 25 ing 22 and carrying a gear 23 by which the member I9 may be driven from a shaft 24 and appropriate speed reduction gearing 25.

cent the radially disposed end portion of the pas- 30 instance, the die I2 is of cy11`n- 35 die and constructed to fit more loosely with` the 40 of the tool during To feed the nut position for entering the die recess, the blanks are .45

axial alinement stack and forced through the serrating die 2 into 5,5Y

- means of a plunger vping tool and the operative engagement with the threading tool by longitudinal reciprocation through the space between the chute 2l and the positioning block 28 and into the open end of the die. The nut engaging end of the plunger is formed with a recess 30 into which the tapering end 3l of the tapping tool may enter in the most advanced position of the plunger.

The plunger is mounted in a manner such that a positive movement will be imparted to the nut blank to force the latter through the trimming die after which the blank is forced into active engagement with the tapping tool under spring action so as to avoid the danger of damaging the tapping tool. To this end, the plunger is formed intermediate its ends with an enlargement 3| slidable in a sleeve 32 which also supports an axially adjustable threaded plug 33 having a recess 34 in which the end of the plunger is received. A spring 35 coiled about the plunger and acting in compression between the enlargement 3l and the plug 33 constantly urges the plunger toward the serrating die a distance determined by the position of an inturned flange 36. The plunger is thus adapted for a limited degree of axial movement relative to the sleeve 32 which in turn is slidable longitudinally of a bore 31 in the frame 2I.

A spring 38 coiled about the sleeve 32 and acting in compression between a shoulder 39 and a cap 43 on the rear end of the plunger tends to retract the sleeve and plunger to the position shown in Fig. l. A follower lI on oneend of a lever 42 pivoted at 43 bears against the cap 49, a roller 44 on the other end constituting the follower of a cam 45 fast on the main drive shaft 4S which is arranged to rotaterin acounterclockwise direction. The cam is driven in synchronism with the tapping tool. This may be accomplished by connecting the main drive shaft and the shaft 24 together through the medium of appropriate gearing 41.

The operation of the mechanism above described is as follows assuming that the parts are positioned as shown in Fig. l and that the tapcurved rod are entirely filled In the assumed position of the parts, the plunger 29 will be fully retracted, a nut blank positioned on the block 29, and the previous blank will have been pa-rtially threaded. As the follower roller 44 rides along the dwell surface 48, the threading operation continues,

with finished nuts.

the nut being held against rotation by virtue of the engagement between its serrations and the mating serrations I5 on the sleeve I6.

When the cam surface 49 encounters the roller 44, the lever 42 is rocked in a direction to project the. sleeve 32 toward the right as viewed in Fig. 1. In the initial part of this movement, the plunger 29 engages the lowermost nut blank 9 and presses the same against the die block I2 whereupon the spring 35 yields until the lost motion between the plunger and the sleeve has been taken up. In the continued movement, the sleeve and plunger will move as a unit, and the plunger will be actuated positively forcing the nut blank through the serrations I3 of the die, the positive movement being arrested slightly short of the position at which the nut blank eiectually engages the cutting elements of the tool I4 which occurs after the nut serrations have passed the die serrations.

The position of the sleeve 32 remains xed as the follower 44 rides along the cam surface 50 29 which is mounted for 'threading the internal bore but the forward movement of the plunger continues under the action of the spring 35 yieldably forcing the serrated blank onto the end of the tapping tool. The arrangement is such that by the time the surface 5D passes by the follower 44 permitting retraction of the sleeve 32 under the action of the spring 38, the threading operation will have been Started and a suflcient length of thread cut to insure proper advance of the nut by the rotating tool. During threading, the nut is held effectually against turning by virtue of the engagement between the external serrations on the nut and the internal serrations on the sleeve I6 which fit loosely in order to facilitate advance of the nut by the action of the rotating tool. The cycle is complete as the plunger 29 is retracted to the position shown where it remains during the next dwell period and while the threading is being completed so as to advance the finished nut out of interfering relation with respect to the blank advanced inthe next forward stroke of the plunger.

It will be apparent from the foregoing that the present invention provides for serrating the periphery of a nut blank automatically as an incident of advance thereof into operative engagement with the tool by which the blank is threaded. The serrating and threading operations occur successively but in one continuous axial movement of the blank. In this way, both operations may be performed in one machine not materially more complicated in construction than the machine ordinarily used for threading alone thereby avoiding the necessity of rehandling and repositioning the blanks for the second operation. A high degree of accuracy and low cost of manufacture are thus obtained.

I claim as my invention:

1 A machine for cutting longitudinal serrations around the periphery of a nut blank and threading the internal bore thereof comprising, in combination, a stationary die member having a cylindrical recess serrated to correspond to the serrations to be formed, a plunger axially alined with said recess and adapted to enter one end of the latter, a sleeve supporting saidplunger for a limited degree of relative axial movement, a spring acting between said sleeve and plunger and normally urging the latter toward saiddie member, means forfeeding nut blanks one by one 7 into a position between said die member and said plunger when the latter is retracted, means for moving said sleeve intermittently toward said die member to advance the sleeve relatively to said plunger until the has been taken up against the action of said spring andV then to advance said sleeveand plunger as a unit whereby to force a nut blank positively into said die member a predetermined distance, and a rotating tapping tool disposed within said die member and adapted to enter said bore and activelyengage said blank in the movement of the blank by said spring while said sleeve is dwelling in advanced position.

2. A machine for cutting longitudinal serrations around the periphery of a nut blank and y thereof comprising, in combination, a stationary die member having a cylindrical recess serrated to correspond to the lserrations to be formed,

die member, means for feeding nut blanks one by one into a position between said die member and said plunger when the latter is retracted, means for moving said support intermittently tosaid support is dwelling in advanced position.

3. A machine for cutting longitudinal serrations around the periphery of a nut blank and threading the central successively to the forward end of said die meinber, a plunger reciprocable axially of said die plunger intermittently.

4. A machine for cutting longitudinal serrations around the periphery of a nut blank and threading the internal Vance to cut longitudinal serrations around the periphery of said blank, a threading tool adapted hold the blank against turning.

5. A machine for cutting longitudinal serra- -tions around the serrations and acting on each nut blank in the initial part of the blank against turning, and a rotary tapping tool operating in the latter part of said motion to thread said bore.

6. A machine for cutting longitudinal serraing said tool and for operating said last mentioned means in timed relation.

8. A machine for cutting longitudinal serrations around the periphery of a nut blank and 

